What plug-in hybrid technologies are used in domestic mainstream SUVs? Please open the surface to see the essence

Pure electricity can be used for short-distance, and oil and electricity can be mixed for long-distance and long-distance. These features make plug-in hybrid vehicles the best solution for new energy travel. However, plug-in hybrid vehicles are technically very complicated. This has led to more stringent requirements for technology and vehicles, and the current mainstream plug-in hybrid SUVs are concentrated between 200,000 and 300,000 yuan. What are the hottest models nowadays? What is the difference?

From the point of view of the existing hybrid system, it can be divided into three types: 'tandem type', 'parallel type' and 'hybrid type'. The simplest is a series structure, relying only on a single drive system, but on performance. The increase is obviously not enough; while the parallel type can be both motor-driven and engine-driven, but economical smoothness is not the best; instead, 'hybrid' style combines the advantages of the first two. , It is also the most used form of hybrid vehicles.

For the current domestic mainstream hybrid plug-in hybrid SUVs with a sales volume of RMB 20,000 to RMB 300,000, a mixed type of “hybrid connection” is used. However, there is a difference between the architecture and hardware components and operating mode. The major difference is that the most popular models are WEYP8, SAIC Roewe eRX5 and BMW Brilliance X125Le.

WEYP8: Introduction to the New Pi4 Platform

The WEYP8 adopts the new Pi4 platform independently developed by Great Wall Motors. The core technology of the platform is plug-in hybrid system, intelligent and four-wheel drive technology (complete decoupling of front and rear axles). The hardware is divided into front axle. In the rear axle area, there is no drive shaft in the middle, but intelligent four-wheel drive can also be realized.

The front axle section is composed of a 2.0T turbocharged engine and a 6DCT dual clutch transmission. The emphasis is on adding a BSG motor to the front wheel train of the engine. The rear axle section is the core of the Pi4 platform. Here, the drive motor is a three-element lithium battery. The group, the drive motor control and the BSG controller, and the newly added 2-speed reducer are combined.

The advantages and disadvantages of the new Pi4 platform:

The new BSG motor on the front axle is mainly used to start and stop on the predecessor technology, and the hybrid technology of motor Boost and energy recovery makes the whole vehicle's power performance 30% higher than that of the same displacement fuel truck. The rear axle part The added 2 speed reducer is to ensure that the motor can be in a highly efficient state at any time, and improve the vehicle's good performance at high speed.

At the same time, the Pi4 platform also has some disadvantages. In order to realize more comprehensive security, the battery pack on the rear axle is placed in the position under the luggage compartment, and in combination with higher standards of security is indeed very safe, but There will be a certain influence on the space of the luggage compartment.

The hybrid system of the BMW X125Le consists of only a 1.5T three-cylinder turbocharged engine and a motor. The engine is arranged on the front axle to drive the front wheels, and the motor is arranged on the rear axle to drive the rear wheels. However, four-wheel drive can only be achieved in certain modes.

In the EV mode, the engine does not start at this time, the battery powers the motor on the rear axle, the motor drives the rear wheels, and the vehicle is in the rear drive mode, which is also consistent with the characteristics of BMW. In the engine drive mode, at this time When the engine is started, the vehicle is driven and the battery is charged. At this time, the motor on the rear axle does not work and the vehicle becomes the front drive mode. In the hybrid mode, the engine and the motor work simultaneously, driving the front wheels and the rear wheels, respectively. At this point the vehicle has become a four-wheel drive mode.

The advantages and disadvantages of the BMWiPerformaceeDrive structure:

It is worth mentioning that if the full throttle pedal triggers BMW's exclusive eBoost supercharged mode, the high-powered starter connected to the engine on the front axle will also participate in the force, providing an additional 60Nm of torque to help drive the vehicle. In this special situation, the BMW X125Le becomes a driving mode for the 'Three Engines'.

The BMW X125Le can only achieve 4WD driving in hybrid mode. In other cases it has both predecessor and reardrive. For most of the city's road conditions, it will be driven by the future. It can be said that the BMW X125Le is based on the reardrive features of the reserved brand. Using a relatively conservative technical route, it abandoned the all-time four-wheel drive and also brought about performance compromises.

SAIC Roewe eRX5: Introduction to the New BSG+TM Architecture

The hybrid system of the BSG+TM dual-motor structure of SAIC is mostly based on motor drive in most cases. If the structure is relatively complicated, it is easier to run.

This hybrid system consists of an engine, an electric drive transmission (with integrated ISG motor and TM motor), a hybrid control unit, a battery pack and a motor controller, etc. Since the engine, the ISG motor and the TM motor are neatly allocated With cooperation, can achieve pure electric, engine direct drive, driving charge, hybrid (series, parallel) driving mode, but eRX5 only has a predecessor mode.

In the pure electric mode and with sufficient power, the TM motor is responsible for driving the wheels, while the engine and the ISG motor are not operated. When the vehicle is cruising at medium and high speed, the direct drive mode is entered at this time. Both motors are Does not work. When battery power is low, vehicle speed and torque demand are not high, part of the engine power to drive the vehicle, another part of the power through the ISG to generate power to the battery, this is the driving charge mode. And mixed mode is divided into series Both parallel and parallel. In series mode, when the battery power is low, the engine will drive the ISG motor to generate power to the battery, TM motor will be responsible for driving the vehicle. The parallel mode is often when the rapid acceleration is needed. Engine, ISG The motor and the TM motor work together to drive the vehicle together to provide powerful power.

Introduction and advantages and disadvantages of the new BSG+TM structure:

However, although this hybrid system is more intelligent, most of the ride through the electric drive is also better, but it is generally in terms of performance. In the future, if the thermal efficiency of the engine and the energy transfer efficiency of the hybrid system can be further improved, and Improve the hybrid control strategy, while driving the motor power and battery energy density can be further improved, the performance of the entire system will be more perfect. Simple understanding: The hybrid structure of the BMW Brilliance X125Le is mostly driven later, so It also continues the essence of BMW brand control and performance; Roewe's eRX5 has advantages in ride comfort and comfort because it is basically driven by a motor; and the optimized Pi4 architecture on WEYP8 takes into account the former two. Advantage.

Why does WEYP8 qualify for direct X1PHEV?

In fact, apart from the three types of 'series', 'parallel' and 'hybrid' in the structure of hybrid power, according to the position of the engine in the structure of the hybrid system, there are different structures of the hybrid system in the industry. , where 'P' is the meaning of position, represents the position of the drive motor in the hybrid system, and is currently divided into five categories, P0 to P4, depending on the location:

P0: The drive motor is located at the front end of the engine and is connected with the pulley. P1: The drive motor is located in the engine. The electric drive system directly drives the crankshaft. P2: The drive motor is located between the engine and the transmission, that is, the input shaft of the transmission. P3: The drive motor is located. Transmission output shaft end; P4: Drive motor position is separated from the engine and gearbox, generally used to drive non-powered wheels.

In simple terms, 'P0' is the most concise hybrid architecture, ie 'weakly mixed'; 'P1' is designed specifically for the engine and cannot realize pure electric function; 'P2' allows the hybrid mode to be more flexible. A separate clutch is added for control in the middle, but the space in the vehicle is affected, and the engine needs to be miniaturized.

'P3' can be regarded as the beginning of a parallel structure, but it can not realize the intelligent start and stop of the engine; 'P4' is a better display of the parallel structure, but it needs to be combined with the BSG motor to form a 'P0+P4' architecture to be perfect.

Why is WEYP8 able to compete directly with BMW Brilliance X125Le? The main reason is that their hybrid architecture is the optimal combination of 'P0+P4'. It is only that the structure of BMW Brilliance X125Le is more basic and it also gives up in order to compromise on performance. The electric four-wheel drive system, and WEYP8 on this basis to add the performance of the BSG motor and rear gear reducer, because these two small changes have undergone tremendous changes.

The performance of the 'P0+P4' architecture in daily driving

Most of BMW Brilliance X125Le's driving status is driving in the rear drive mode. The performance is still very good, but there is no intelligent four-wheel drive blessing. The performance in the case of special road conditions is very general.

At the same time, except when the computer determines that a four-wheel drive is needed, it can only be achieved by fully pressing down the accelerator pedal when the eBoost is triggered to achieve the 'four-wheel drive mode'. This is obviously not very smart and practical. The WEYP8's front and rear axle torques can be freely allocated and can be easily implemented in a four-wheel drive system. This, together with the Boost function of the front axle BSG motor, and the rear two-gear reducer that keeps the motor in an efficient state, not only allow WEYP8 has better obstacle performance, but also can easily achieve the best sports performance anytime, anywhere.

It is worth mentioning that, WEYP8 can still retain about 20% of the battery power to deal with the sudden slippage of the vehicle, so the vehicle does not appear to be unable to switch to the four-wheel drive mode because the battery is dead. , WEYP8 achieves the maximum climbing grade of 60% on dry asphalt pavement with climbing performance far beyond its peers.

SAIC Group's EDU system performance in daily driving

Due to the layout and technical features of the engine + BSG motor and TM motor, the Roewe eRX5 is basically driven by the TM motor to drive the front wheels in most cases. At the same time, the entire vehicle has only a pre-drive mode.

Thanks to the advantages of motor output, Roewe eRX5 has better ride and comfort in urban roads, but its performance and acceleration are very mediocre. Simple understanding: Hardware and software adjustment of BMW X125Le hybrid system Both are more inclined to drive in the city, and at the same time, the compromise to performance can also bring pleasant driving experience. However, the fixed-mode four-wheel-drive system is not smart enough to use. The Roewe eRX5 is a model that is completely urban-oriented. The smoothness and comfort are its appeals. WEYP8 not only has comfort and sports, but also uses smarter software algorithms, combined with the adjustment of China's complex roads, in the application of four-wheel drive systems more handy.

Finally, I would like to specifically say that with respect to the SOC setting, in the SAVE mode, the WEYP8 battery SOC can be freely adjusted in the 50-80% range, and the user can more flexibly select the corresponding mode according to the next route.

For example, if there is a long period of time on the highway, then I can set the SOC higher to allow the battery to add more power and further reduce the energy consumption of the vehicle. If the next high speed Not very high, then I can properly set the SOC lower, so that the engine load is not so big. BMW also offers SAVEBattery mode, but it does not provide SOC settings that allow the user to freely adjust, it can only show you The battery power remains at the current value. For example, if your current battery power is 50%, when you turn on the SAVE Battery mode, the battery power level can only be maintained at around 50% and cannot continue to increase. Roewe does not provide SOC settings like BMW. The system can only keep the power in the current mode and cannot continue to increase.

Full text summary: Roewe eRX5 is more suitable for urban use, BMW Brilliance X125Le is more suitable for multi-environment use, and WEYP8 is for each director.